What Is Vital Capacity?
Vital capacity (VC) is the maximum volume of air that can be expelled from the lungs after taking the deepest possible breath. It is one of the most important measurements in pulmonary function testing and reflects the overall capacity of your respiratory system.
A healthy person's vital capacity typically falls between 3 and 5 liters, though it varies significantly based on age, sex, height, and ethnicity. Athletes and tall individuals often have vital capacities exceeding 6 liters.
The Vital Capacity Formula (Baldwin et al.)
This calculator uses the equation developed by Baldwin et al. to estimate predicted vital capacity based on demographic data:
- For females: VC = Height (cm) × (21.78 − 0.101 × Age)
- For males: VC = Height (cm) × (27.63 − 0.112 × Age)
The result is expressed in cubic centimeters (cm³), which equals milliliters (mL). Divide by 1,000 to convert to liters (L).
Unit Systems
- Metric: Enter height in centimeters (cm). Result displayed in liters (L) and milliliters (mL).
- Imperial (American): Enter height in feet and inches. The calculator automatically converts to centimeters for the formula.
How to Use the Vital Capacity Calculator
- Select your sex (male or female) — the formula constants differ by sex.
- Enter your age in years.
- Choose your preferred unit system (metric or imperial).
- Enter your height in the selected units.
- Click "Calculate Vital Capacity" to see your estimated result.
Interpreting Your Results
Your calculated vital capacity is a predicted value — the theoretical normal for a person of your age, sex, and height. Compare it to the reference range:
- Below 3 L: Below normal. May be associated with restrictive lung disease (e.g., pulmonary fibrosis, obesity, chest wall deformities).
- 3–5 L: Normal range for most adults.
- Above 5 L: Above average — common in tall individuals and trained athletes.
Vital Capacity vs. Other Lung Capacities
Vital capacity is one of four standard lung capacities measured during spirometry:
| Capacity | Formula | Description |
|---|---|---|
| VC — Vital Capacity | IRV + TV + ERV | Maximum air exhaled after maximum inhalation |
| TLC — Total Lung Capacity | VC + RV | Total volume of air lungs can hold |
| IC — Inspiratory Capacity | IRV + TV | Air inhaled from normal resting state |
| FRC — Functional Residual Capacity | ERV + RV | Air remaining after normal exhalation |
Where: IRV = Inspiratory Reserve Volume, TV = Tidal Volume, ERV = Expiratory Reserve Volume, RV = Residual Volume.
Vital Capacity in Lung Disease
Measuring vital capacity helps clinicians differentiate between types of lung disease:
- Restrictive lung disease (e.g., pulmonary fibrosis, pleural effusion): VC is decreased, as the lungs cannot expand fully.
- Obstructive lung disease (e.g., COPD, asthma): VC is usually normal or only slightly reduced, but airflow is impaired.
Disclaimer
This calculator provides an estimated predicted value based on the Baldwin et al. equation. The result is for informational and educational purposes only. It cannot replace a professional spirometry test or medical evaluation. Always consult a qualified healthcare provider for diagnosis and treatment.